The present invention relates to a passive safety belt arrangement for vehicles, and more particularly, to a control switching arrangement for safety belts in which one end of the belt is driven between a releasing position and a restraining position.
In the use of vehicles, in particular passenger automobiles, many riders have found the attachment and release of the safety harness to be an awkward and inconvenient task. In order to automate this operation, so-called passive-type safety harness arrangements have previously been proposed. With these passive-type arrangements a slide or traveler attached to one end of the harness is designed to be propelled along a track on the frame of the vehicle between a release position, where the harness is held away from the body of the rider, and a restraint position, in which the harness is brought into contact with the body of the rider. It is typically propelled by means of an actuating element that is rigid in tension and compression. The traveler is located at one end of the actuating element, which element is driven in either longitudinal direction by a motor, for example an electric motor. The actuating element may be made in the form of a flexible shaft of the type known to be used to operate lowerable vehicle windows or the like. This type of shaft includes a steel cable spirally wound with a steel wire helix.
To control the motor, in particular to switch it off upon completion of the travel of the actuating element, limit switches associated with the two extreme positions of the traveler are provided in the track. One of these switches is arranged at the end of the track corresponding to the restraint position of the harness and is actuable by a stud provided at the end of the actuating element holding the traveler. In earlier German Application Pat. No. 2726261, which is directed to an actuating device for a passive restraint harness system, it was proposed that the other limit switch, assigned to the release position of the traveler, be arranged at the other end of the track. This release position switch, like the restraint switch, is actuable by the stud provided at the traveler end of the actuating element. However, this previous arrangement has the disadvantage that the limit switch assigned to the release position is located in a region of the vehicle interior adjacent the windshield post, which region is a possible point of impact of the rider's head during an accident. As a result this region should be kept clear of any hard and dangerous projections. Furthermore, this particular post is designed as slender as possible, so that there is hardly any room for a recessed mounting of such a switch, or even its wiring.